"Arachnophilia! Using Museums to Understand and Conserve Arachnids" - An Interview with Jacob Gorneau and Kate Montana

 By Sabine Fuchs, Katherine Branson School

Spiders and scorpions and arachnids, oh my! The study of these “creepy crawlies,” their evolution, habitat, and, for some, their mysterious bioluminescence, is explored by Jacob Gorneau and Kate Montana at the California Academy of Sciences. Gorneau, who received his bachelor’s in entomology from Cornell University and his master’s in Biology at San Fransisco State University, is a research assistant in the Entomology department at the Academy of Sciences. Montana, who received her undergraduate degree in biology and anthropology, is currently a graduate student researcher in the arachnology lab at the California Academy of Sciences. Gorneau and Montana have worked together using morphological and molecular data to revise the evolutionary history of the marronoid clade of spiders. Jacob and Kate presented Arachnophilia! Using Museums to Understand and Conserve Arachnids at Marin Science Seminar on February 8, 2023. Kate and Jacob were kind enough to answer some questions about their fascinating work surrounding arachnids.

Kate Montana in the field.

1. Jacob: You discussed how scorpions are found in a wide variety of climates. What traits do scorpions possess that make them so adaptable? Are there large differences between scorpions that live in a forest compared to those that live in the desert? 

Physically, scorpions are quite similar even though they are found in a wide range of habitats and climates — fossils of scorpions from nearly 400 million years ago look exactly as scorpions look today! The main exception is some cave-dwelling scorpions no longer have eyes, which is a common phenomenon in animals that exclusively live in caves. Scorpions do, however, have specific habitat preferences that we call microhabitats, and these are generally pretty consistent regardless of the climate and often involve darker spaces like burrows that are, in the case of deserts, generally slightly more humid than the surrounding landscape. This also helps them escape the extreme weather conditions that they can experience in deserts. Scorpions also have a strong exoskeleton that prevents them from losing too much water, and they are so efficient at this that they usually get enough water from their food and never need to drink water.

2. Kate: Since your work centers around fieldwork, what practices do you implement to ensure that the environment is not negatively affected by your studies? 

We take care to be as minimally invasive as possible. We do often collect spiders and scorpions that will be sacrificed for DNA extraction, but we only sample populations that are not in danger of being depleted. We try our best to only take the focal species that we need, though some bycatch does occur. When we do catch something that we did not intend to catch, we reach out to colleagues to find out if it might be useful for their research so as not to waste the specimen. We spread out our sampling geographically, which helps get a wide range of geographic representation as well as keep our sampling to a minimum at any particular site. 

3. Jacob: There is a lot of uncertainty and debate over why scorpions fluoresce under ultraviolet black light. As scientists and researchers, what explanation(s) are you most drawn to? 

Thoughts about why scorpions fluoresce range from allowing scorpions to navigate using the sky, to recognize members of the same species, or to detect light. While I personally find the idea that scorpions can use fluorescence under ultraviolet light to somehow navigate using the stars or moon really exciting, I think the fluorescence might more likely be a tool for simply detecting light. There have been a few studies showing this, and this idea makes sense to me because it seems like a good way for a scorpion to detect the time of day by the amount of sunlight present, as well as being able to detect when it has found shelter, such as in a burrow.

Jacob Gorneau in the field.

4. Kate: What does the process of revision of the evolutionary history of a species look like, and how does this revision impact the scientific world?

We start with a thorough search of the scientific literature to find out all we can about what is already understood about a particular species, genus, family, or other designation of a group of organisms. We use tools like Google Scholar or the library to find papers that contain this information. Then we can decide which samples we need in order to answer our question about how one particular species or genus is related to others in the spider tree of life. In addition to the samples that we are directly interested in, we need outgroups—taxa whose relationship we already know to our focal species in order to root the tree. Then we can collect both molecular data through DNA sequencing and morphological data through careful observation of the physical characteristics of the organisms. We take these data and run various computational analyses in order to produce a phylogeny that will visualize the evolutionary relationships between species. The scientific community can then use this tree of life to inform questions about behaviors, range of species, species interactions, and morphological characteristics. Since evolution is the process by which all organisms come to be the way they are, we need a solid understanding of the intricate evolutionary relationships between organisms in order to fully understand how they came to be.

5. Jacob: You explained that cattle grazing has impacted scorpion habitats since it compacts the earth, which prohibits scorpions from burrowing. In what other ways are humans negatively impacting scorpions or their habitats? 

In California, there are two other main threats to scorpions and their habitats: wildfires and land development. Firstly, while wildfires are an important and natural part of California’s ecosystem, the way that humans manage land today has resulted in wildfires larger in scale and intensity than they have ever been before. We don’t know if scorpions can survive these wildfires. Since scorpions are slow dispersers, meaning they move through the environment quite slowly and can’t run away from a fire, populations that exist where major wildfires have occurred might go extinct. Similar to how wildfires might block out groups of scorpions, developing land, either because of agriculture or building construction, can also remove important scorpion habitats. One way to combat this issue is contributing to wildlife corridors or making sure that as land is developed, there is enough connected natural land for organisms to move freely. People often think of wildlife corridors in terms of larger animals, but this connectivity of habitats is also useful for scorpions.